I need some electronics advice

[Zambini]

Okay, so for my physics class I'm doing a project where I am gonna use solar panels, Wall plug, and some Duracell Batteries to charge an iPod and find the costy-ness of all 3.

SO what I need help with is:
a) I believe that I can use 4 of these:
FRYS.com*|*OWI
OWI 608 Solar Battery
Which is 350mA, and 1.4v. So I will have 5.6v. Which should be good
for USB, right?
Then I will need a way to put the power taken from the solar panels to an iPod or other USB powered device

b) I'll just buy a wall socket USB plug and a volt meter to see how much power it takes to charge it (recommendations on the type of equipment to use?)

c) then I will need help choosing a group of batteries (any type of battery (AA, AAA, C, D, 9v, w/e) ) and converting that energy into a ~5v USB plug



Thanks for all your help. I am gonna do this over the next week (Spring Break)

[garetjax]

Mythbusters recently aired a segment to find out whether or not it was more cost effective to leave a light on when you leave a room for a few minutes, or turn it off the light when you leave, thus potentially saving electricity.

Basically, they found that the start up power needed to turn the light on was almost counter productive than to just leave the lightbulb on the entire few minutes you were gone. In either case, unless you left the room for no more than 20-30 seconds, you weren't saving any electricity at all. The usage was about the same regardless if you turned the light off, or left it on during your abscence.

The reason I bring this up? A lot of the equipment used to measure power generation and usage was described in detail on the show. You might want to look into it.

[Capper]

Originally Posted by garetjax

Mythbusters recently aired a segment to find out whether or not it was more cost effective to leave a light on when you leave a room for a few minutes, or turn it off the light when you leave, thus potentially saving electricity.

Basically, they found that the start up power needed to turn the light on was almost counter productive than to just leave the lightbulb on the entire few minutes you were gone. In either case, unless you left the room for no more than 20-30 seconds, you weren't saving any electricity at all. The usage was about the same regardless if you turned the light off, or left it on during your abscence.

The reason I bring this up? A lot of the equipment used to measure power generation and usage was described in detail on the show. You might want to look into it.

Actually, i watched that episode, and of the 30+ bulbs tested, every single one should be turned off rather than leaving it on...

[robodude666]

Hey,

Keep in mind that USB is 5v @ 500mA. That Solar Panel is only 350mA. Solar power these days is not very efficient. Are you required to use it as a power source?

As for the equipment... I would recommend getting a good multimeter. There are many good ones out there that can measure current, resistance and voltage among other funky things. However, a good meter will set you back a healthy amount. I bought mine for $80 at Radio Shack almost a year back and it served me well.

If you want to use rechargeable batteries, the bigger the battery the larger its mAh rating. However, since you need 5v, getting a pack of 5 AA batteries should set you good. C and D batteries have a larger mAh rating which means they can run longer.

Do you have to use an iPod? They suck ><

I can tell you right off the bat that Solar Power is the least cost effective method. Solar cells can not capture all the energy nor the entire spectrum and a lot of the energy is lost. Plus they are very expensive to manufacturer.

EDIT: A device similar to what Mythbusters used is the kill-a-watt. It measures wattage, voltage and current usage of your outlet. It can be adapted to this project with a spare power cord.

EDIT2: I am doubting the quality of that solar panel. Its only $10 for 1.4v @ 340mA. Most "good" panels with those ratings would cost about $20-30.

Best of luck on your project!
-robodude666

[garetjax]

Originally Posted by Capper

Actually, i watched that episode, and of the 30+ bulbs tested, every single one should be turned off rather than leaving it on...

Hmm. Are you sure? I could have swore that the difference between the light being turned off versus being left on was neglible at best where power consumption was concerned.

Originally aired on Decemver 13, 2006, episode 69.

Complete transcript follows, taken from THIS link:

Lights On or Off

Myth: You save on energy bills by leaving lights on. Some people believe that the energy to turn on lights exceeds savings of turning lights off.

They talked to Mark Reisfelt, manager of the Independent Electric Supply where they purchased their light bulbs. He felt that it was best to turn the lights off.

To test the myth, they needed to measure energy usage during startup, maintenance (steady state), and shutdown.

For steady state energy consumption, they turned on several different types of bulbs for 60 minutes and measured their consumption using a Kill A Watt:

• Incandescent 90 Wh
• Compact Fluorescent (CFL): 10 Wh
• Halogen: 70 Wh
• Metal halide 60 Wh
• LED: 1 Wh
• Fluorescent: 10 Wh

For startup energy consumption, Grant hooked up an inductive current loop to a computer and measured the amount of energy used when the turned on the bulbs. With an inductive current loop, you run a wire through the center, which induces a current in the loop. This current is then measured by a digital sampling oscilloscope.

Based on the amount of energy consumed turning on the bulb, they were able calculated how long the bulb would have to be turned off in order to make it worth the energy savings, i.e. "It's best to turn off the bulb if you are leaving the room for":

• Incandescent: 0.36 seconds
• CFL: 0.015 seconds
• Halogen: .51 seconds
• LED: 1.28 seconds
• Fluorescent: 23.3 seconds

In other words, its almost always best to turn the bulb off. Even the 23 seconds for the fluorescent lights isn't very long, and the rest of the times are pretty much blinks of an eye.

Bulb Longevity

They tested one final element of this myth: frequently turning lights on and off decreases their life span, thus leading to greater costs. Grant setup a timer and relay to turn the bulbs on and off repeatedly every 2 minutes. After six weeks, only the LED bulb was still working. Based on this test, they extrapolated that it would take five years of ordinary usage to cause the bulbs to burn out.


*Edit* Looks like you were right, Rich. ;)

*Double Edit* This may or not be useful, Zambini:

For startup energy consumption, Grant hooked up an inductive current loop to a computer and measured the amount of energy used when the turned on the bulbs. With an inductive current loop, you run a wire through the center, which induces a current in the loop. This current is then measured by a digital sampling oscilloscope.

[Zambini]

Well,
a) I only have a budget of $100 bucks (yay California Science Grants!)
b) I need to get the parts VERY QUICKLY
c) Fry's or radio shack would be the best places because they are close


As for what resistors or w/e I need, I have no clue =/

[robodude666]

Originally Posted by Zambini

Well,
a) I only have a budget of $100 bucks (yay California Science Grants!)
b) I need to get the parts VERY QUICKLY
c) Fry's or radio shack would be the best places because they are close


As for what resistors or w/e I need, I have no clue =/

Well, resistors and w/e won't really be needed since you are just connecting a battery to a device. You may need a 10uF cap to stabilize it but im not sure.

[onebxr]

use a potato.:)